The moment Mossad agents got their man?

CCTV footage shows 'killers' outside suite of murdered Hamas militant

The violent death of Mahmoud al-Mabhouh in a luxury Dubai hotel was another chapter in the long and blood-soaked politics of the Middle East.

But last month's killing of the Palestinian militant provoked a furious international row yesterday, following the release of extraordinary CCTV images purporting to show the moments before the Hamas chief's mysterious assassination, and denials by London and Dublin that the alleged killers were British or Irish nationals.

Authorities in Dubai said on Monday that six of the assassins entered the United Arab Emirates for their secret mission on UK passports, while the remainder used Irish, French or German travel documents.

But last night the British government said it believed that six UK passports identified by officials in the Gulf state as having been used in the assassination were "fraudulent". The three Irish passports were dismissed by officials in Dublin as forgeries.

As Israel declined to comment on speculation – also by Hamas – that the operation was carried out by the Israeli intelligence agency, Mossad, the British embassy in Tel Aviv announced that a UK investigation had been launched.

At least two British passport-holders living in Israel, who have the same names as those used by the alleged assassins, expressed alarm at the apparent appropriation of their identities by the assassins. Paul Keeley told The Independent last night: "I don't know how my name could have come to be used, and that's a question I would like an answer to."

Video footage recorded at the five-star al-Bustan Rotana Hotel catches Mr Mabhouh, 49, arriving alone. The killers, disguised as sporting tourists, then move into place and trail him, even riding in the same lift as him to establish his room number. They return later and wait for their victim, who was suffocated, possibly following electrocution and torture.

The killers spent less than 19 hours in Dubai. They arrived on separate flights, paid the hotel in cash and took rooms as close as possible to Mr Mabhouh. "Gail Folliard", the only woman, played a key part in the surveillance operation. In her passport photo she is blonde, but the CCTV film shows her wearing a dark wig as she watches him in the hotel lobby while pretending to make a telephone call. The four men who carried out the killing carried sports bags and tennis rackets. They are seen seen entering the lift together as they go upstairs and wait for the Hamas official in Room 230.

Mossad has a long history of using foreign documents to carry out operations abroad. In 1997, an Israeli hit-squad used Canadian passports in a bungled assassination bid on a Hamas leader, Khaled Meshaal, in Jordan.

The UAE has requested international help in the murder inquiry. The emirate's police chief, Dahi Khalfan Tamim, did not directly accuse Mossad of culpability but declared: "Leaders of certain countries gave orders to their intelligence agents to carry out the killing."

Mr Mabhouh was wanted in Israel for involvement in the 1989 abduction and murders of two off-duty soldiers. Officials in Tel Aviv claim he was in Dubai en route to Iran to obtain arms. But the bitter enmity between Hamas and its rival Palestinian faction Fatah may also have contributed to Mr Mabhouh's death. Two Palestinians have been arrested in Jordan in connection with the assassination.

Yesterday's British embassy statement is understood to have been issued on the grounds that the signatures and photographs did not correspond to any in passports issued by the Foreign and Commonwealth Office (FCO). The other names of "Britons" cited by Dubai in the plot were Michael Lawrence Barney, James Leonard Clarke, Jonathan Louis Graham, Paul John Keeley and Stephen Daniel Hodes. The FCO and Scotland Yard were trying to trace the individuals.

Ireland's Department of Foreign Affairs said it had no record of any passports being issued under the names of Gail Folliard, Evan Dennings and Kevin Daveron. The French and German authorities said the passports of a "Peter Elvinger" and a "Michael Boenheimer" had also been forged.

Mr Keeley, a expat builder originally from the London borough of Havering, said he had been in "a daze" since hearing his name had cropped up in the Dubai case. "It's like being in a kind of daydream. It's a bit strange. I haven't been abroad for two years."

Mr Keeley, who holds both a British and Israeli passport and says he has never lost either, said: "The last time I was out of the country was for a couple of days in Turkey." Mr Keeley, who lives south of Haifa, said he had not been contacted by either British or Israeli authorities and added: "I would like some answers but I don't really know who to phone."

He said he had no opinions about the operation itself, explaining: "I'm not really a political person."

The other Briton "in the frame" is Melvyn Adam Mildiner, who lives near Jerusalem. He said: "I went to bed with pneumonia and woke up a murderer. I have no idea how to clear my name. I don't know who chose my name and why. I am angry, upset and scared."

With the picture issued by Dubai police not matching his own, Mr Mildiner added: "It's not me, which is one silver lining on this entire story because at least I can point to it and say, 'Look, that's not me. I have my passport.' It is in my house, along with the passports of everybody else in my family, and there's no Dubai stamps in it because I've never been to Dubai."

Mr Tamim said he was puzzled by the lack of security for Mr Mabhouh. "Hamas did not tell us who he was. He was walking around alone. If he was such an important leader why didn't he have people escort him?" he said.

The assassination has dominated Israeli media, with some commentators expressing admiration for the operation, while pointing out that the ubiquitous presence of CCTV as well as instantly accessible computer data has significantly complicated such assassinations. "These days, any border policeman has near-instant access to international databases where he can authenticate documents," Gad Shimron, a former Mossad field officer, told Reuters. "That means that passports used by spies have to be as close as possible to the real thing."

False identities: The passports used by the killers

Of the 11 passport photographs released in Dubai, 10 have been declared bogus. The Foreign Office in London said the six apparently British suspects' passports were faked, the Irish government said its passport-holders did not exist, and the German government declared the passport number wrong. France said it could not confirm the nationality of Peter Elvinger. So far, at least two Britons living in Israel whose names were used in the documents have declared their bafflement at the news. Neither matches the relevant passport picture.

Evan Dennings, Irish

Gail Folliard, Irish

James Leonard Clarke, British

Jonathan Louis Graham, British

Michael Bodenheimer, German

Paul John Keeley, British

Michael Lawrence Barney, British

Peter Elvinger, French

Kevin Daveron, Irish

Melvyn Adam Mildiner, British

Stephen Daniel Hodes, British